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Enhancing predictability of IDH mutation status in glioma patients at initial diagnosis: a comparative analysis of radiomics from MRI, [ 18F]FET PET, and TSPO PET. Eur J Nucl Med Mol Imaging 2024:10.1007/s00259-024-06654-5. [PMID: 38396261 DOI: 10.1007/s00259-024-06654-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/10/2024] [Indexed: 02/25/2024]
Abstract
PURPOSE According to the World Health Organization classification for tumors of the central nervous system, mutation status of the isocitrate dehydrogenase (IDH) genes has become a major diagnostic discriminator for gliomas. Therefore, imaging-based prediction of IDH mutation status is of high interest for individual patient management. We compared and evaluated the diagnostic value of radiomics derived from dual positron emission tomography (PET) and magnetic resonance imaging (MRI) data to predict the IDH mutation status non-invasively. METHODS Eighty-seven glioma patients at initial diagnosis who underwent PET targeting the translocator protein (TSPO) using [18F]GE-180, dynamic amino acid PET using [18F]FET, and T1-/T2-weighted MRI scans were examined. In addition to calculating tumor-to-background ratio (TBR) images for all modalities, parametric images quantifying dynamic [18F]FET PET information were generated. Radiomic features were extracted from TBR and parametric images. The area under the receiver operating characteristic curve (AUC) was employed to assess the performance of logistic regression (LR) classifiers. To report robust estimates, nested cross-validation with five folds and 50 repeats was applied. RESULTS TBRGE-180 features extracted from TSPO-positive volumes had the highest predictive power among TBR images (AUC 0.88, with age as co-factor 0.94). Dynamic [18F]FET PET reached a similarly high performance (0.94, with age 0.96). The highest LR coefficients in multimodal analyses included TBRGE-180 features, parameters from kinetic and early static [18F]FET PET images, age, and the features from TBRT2 images such as the kurtosis (0.97). CONCLUSION The findings suggest that incorporating TBRGE-180 features along with kinetic information from dynamic [18F]FET PET, kurtosis from TBRT2, and age can yield very high predictability of IDH mutation status, thus potentially improving early patient management.
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Perifocal Edema in Patients with Meningioma is Associated with Impaired Whole-Brain Connectivity as Detected by Resting-State fMRI. AJNR Am J Neuroradiol 2023:ajnr.A7915. [PMID: 37385680 PMCID: PMC10337612 DOI: 10.3174/ajnr.a7915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 05/28/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND AND PURPOSE Meningiomas are intracranial tumors that usually carry a benign prognosis. Some meningiomas cause perifocal edema. Resting-state fMRI can be used to assess whole-brain functional connectivity, which can serve as a marker for disease severity. Here, we investigated whether the presence of perifocal edema in preoperative patients with meningiomas leads to impaired functional connectivity and if these changes are associated with cognitive function. MATERIALS AND METHODS Patients with suspected meningiomas were prospectively included, and resting-state fMRI scans were obtained. Impairment of functional connectivity was quantified on a whole-brain level using our recently published resting-state fMRI-based marker, called the dysconnectivity index. Using uni- and multivariate regression models, we investigated the association of the dysconnectivity index with edema and tumor volume as well as cognitive test scores. RESULTS Twenty-nine patients were included. In a multivariate regression analysis, there was a highly significant association of dysconnectivity index values and edema volume in the total sample and in a subsample of 14 patients with edema, when accounting for potential confounders like age and temporal SNR. There was no statistically significant association with tumor volume. Better neurocognitive performance was strongly associated with lower dysconnectivity index values. CONCLUSIONS Resting-state fMRI showed a significant association between impaired functional connectivity and perifocal edema, but not tumor volume, in patients with meningiomas. We demonstrated that better neurocognitive function was associated with less impairment of functional connectivity. This result shows that our resting-state fMRI marker indicates a detrimental influence of peritumoral brain edema on global functional connectivity in patients with meningiomas.
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P15.09.A Canny edge detection algorithm for quantitative differentiation between diffuse and circumscript glioma growth patterns on MRI. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Lower grade gliomas show heterogenous appearance on T2-weighted MRI. Some tumors grow diffusely along axonal structures whereas others distort adjacent brain tissue through local mass effect. The diagnostic, therapeutic and prognostic implication of differential growth patterns on MRI remain unknown and are difficult to assess quantitatively.
Material and Methods
A web-based application allowing for image preprocessing and providing a comprehensive edge detection tool by means of quantifying tumor border delineation on T2-weighted images based on the canny edge detection algorithm was developed. A sigma value between 1 and 100 determined the threshold where tumor borders where not detected by the algorithm anymore, with 1 equating to the lowest threshold and thus detection of all edges contained in the image. Two experienced faculty members assigned sigma values to axial T2 images of a random sample of 20 WHO grade 2 astrocytomas, IDH-mutant and 1p/19q-non-codeleted. The sigma values were then compared with a binary, subjective rating by the same faculty staff according to the perceived predominant growth pattern (diffuse versus circumscript) of each glioma.
Results
When subjectively categorizing tumors binarily (diffuse versus circumscript), there was moderate interrater variability between observers (cohen’s kappa=0.6). Raters agreed in 16 of 20 cases, terming 7 gliomas unanimously diffuse and 9 gliomas circumscript. In 4 cases, the raters opinions diverged. The sigma values differed significantly between diffuse and circumscript tumors in both raters (rater 1, p=0.002; rater 2, p=0.018). For rater 1, the mean sigma difference between diffuse and circumscript tumors was 10.7 and 9.3 for rater 2.
Conclusion
Edge detection algorithms can be efficiently applied on MRI scans and are highly accurate in differentiating diffuse from circumscript gliomas. Objectification demands defining imaging criteria for diffuse and circumscript appearance of lower grade gliomas on MRI.
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OS03.4.A In vivo dynamics and anti-tumor effects of EpCAM-directed CAR T-cells against brain metastases from lung cancer. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Lung cancer patients are at a particularly high risk for brain metastases, and a considerable number of affected patients succumb due to their intracranial disease. Chimeric Antigen Receptor (CAR) T-cells emerged as a powerful class of cell-based immunotherapy for hematological malignancies. However, it remains unclear whether CAR T-cells also represent a safe and effective therapeutic option for brain metastases.
Material and Methods
A fully syngeneic orthotopic cerebral metastasis model in mice was established by combining a chronic cranial window with repetitive intracerebral two-photon laser scanning microscopy. This approach enabled the in vivo characterization of red fluorescent CAR T-cells and tumor cells on a single-cell level over weeks. Intraparenchymal injection of Lewis lung carcinoma cells (expressing the tumor cell-antigen EpCAM) was performed, and CAR T-cells directed against EpCAM (EpCAMCAR T-cells) were injected into the adjacent brain parenchyma after solid brain tumors have formed.
Results
All mice had visible tumor take four days after the intracranial tumor cell injection, and rapid growth of solitary lesions was seen in the following days. No toxicities mediated by intracranially injected EpCAMCAR T-cells were encountered. In mice treated with EpCAMCAR T-cells, we initially observed substantial CAR T-cell accumulation within the tumor compared to controls (median number: 1700 versus 939 cells/mm2; p = 0.007). This was paralleled by lower velocities of EpCAMCAR T-cells, characterizing T-cell receptor (TCR)-mediated antitumor cytotoxicity due to long-lasting contacts between effector immune cells and tumor cells. Consequently, treatment with EpCAMCAR T-cells resulted in reduced tumorous growth as determined per in vivo microscopy (median tumor area on day 10: 1.8 versus 10.8 mm2; p = 0.001) and immunohistochemistry of excised brains (median tumor volume on day 10: 3.6 versus 33.2 mm3; p = 0.001). However, the number of EpCAM-directed CAR T-cells within the tumor markedly decreased during the observation period, pointing towards insufficient persistence of EpCAM-directed CAR T-cells. In line with these findings, survival was prolonged in mice receiving EpCAMCAR T-cells but long-lasting remission was rare (median survival: 15 versus 13 days; p = 0.012).
Conclusion
Our findings indicate that CAR T-cells injected into the cerebral parenchyma may induce relevant anti-tumor effects in brain metastases from lung cancer. Due to the translational nature of our study, prospective clinical cohorts appear warranted. Strategies improving the intratumoral persistence of CAR T-cells in brain metastases may be utilized to further boost the success of such promising therapy.
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P11.51.B Initial temozolomide monotherapy without radiotherapy might be of limited benefit in the treatment of astrocytoma, IDH-mutant, CNS WHO grade 2 and 3. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The role of temozolomide chemotherapy alone in isocitrate dehydrogenase (IDH-) mutant astrocytomas has not been conclusively determined. Radiotherapy might be superior to temozolomide alone. Recent studies have linked temozolomide therapy with poor clinical course and induction of hypermutation in IDH-mutant gliomas.
Material and Methods
In this retrospective, single-center study, 183 patients with astrocytoma, IDH-mutant, CNS WHO grade 2 or 3 according to WHO 2021 and diagnosed between 2000 and 2019 were included. Patients initially monitored by means of a wait-and-scan strategy, or treated with radiotherapy alone, or receiving temozolomide alone after histological sampling through biopsy or tumor resection were studied. Patient-related, clinical and imaging data were correlated with progression-free and overall survival. A matched-pair analysis accounting for post-surgical tumor volume was conducted.
Results
No significant differences in median age and clinical status at diagnosis was seen. WHO grades were balanced between patients treated with radiotherapy and temozolomide, but the proportion of WHO grade 2 gliomas was higher in the wait-and-scan cohort. Radiotherapy was associated with significantly longer overall survival than temozolomide (in years, 14.4 vs 10.7; p=0.02) and longer progression-free survival than temozolomide (in years, 6.2 vs 3.4, p=0.02) and wait-and-scan strategies (in years, 6.2 vs 4; p=0.03). Comparing wait-and-scan with temozolomide, survival was significantly longer in the wait-and-scan cohort (in years, not reached vs 10.7, p<0.0001). An analysis of WHO grade 2 astrocytomas only also showed superior survival in the wait-and-scan cohort as compared to temozolomide (p=0.02). Of note PFS was similar overall and in WHO grade 2 astrocytomas.
Conclusion
The results suggest superiority of radiotherapy alone over temozolomide alone or wait-and-scan strategies in IDH-mutant WHO grade 2 and 3. Recent study results indicating that temozolomide might compromise prognosis in some IDH-mutant gliomas might be supported by our data, although caution in interpretation of retrospective data is required. The potential negative effects may only be apparent in the long-term.
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Physician Health: Results and Caveats from Surveys in Austria, Switzerland and Germany. Eur Psychiatry 2022. [PMCID: PMC9566831 DOI: 10.1192/j.eurpsy.2022.89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: Surveys assessing alcohol use among physicians most commonly employed the Alcohol Use Disorders Identification Test (AUDIT) or the AUDIT-C. As with other screeners, prevalence estimation is dependent on the accuracy of the test as well as choice of the cut-off value. The aim of the current study is to use samples from various countries derive more precise prevalence estimates of alcohol problems in physicians by correcting for false positive and false negative results using samples from various countries Method: At the Congress of the German Association of Psychiatry, Psychotherapy and Psychosomatics, 2005 in Berlin, 1800 questionnaires, which included the AUDIT-C were distributed among the attending participants. 936 questionnaires (52%) were returned. Also, the data are compared to a second study, performed in Salzburg, Austria to further elucidate the situation. The screening results will be presented and compared to the values when using a correction- formula using data from a general population sample on sensitivity and specificity of the AUDIT-C. Results: Based on the results of AUDIT-C and using a cut-off of 5 for both sexes, 24.1% of the sample of 887 physicians of the German sample are problematic drinkers (14.7% in female and 32 % in male physicians). Using a correction formula leads to markedly lower rates: 6.1% (all), 3.7% (female), 8.1% (male). Discussion: In this large sample, findings clearly confirm that uncorrected screening results lead to severe over-estimation of the prevalence of problematic drinking in physicians. The corrected prevalence rates are lower than in the general population.
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MRI-based contrast clearance analysis shows high differentiation accuracy between radiation-induced reactions and progressive disease after cranial radiotherapy. ESMO Open 2022; 7:100424. [PMID: 35248822 PMCID: PMC9058918 DOI: 10.1016/j.esmoop.2022.100424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 11/26/2022] Open
Abstract
Background Pseudoprogression (PsP) or radiation necrosis (RN) may frequently occur after cranial radiotherapy and show a similar imaging pattern compared with progressive disease (PD). We aimed to evaluate the diagnostic accuracy of magnetic resonance imaging-based contrast clearance analysis (CCA) in this clinical setting. Patients and methods Patients with equivocal imaging findings after cranial radiotherapy were consecutively included into this monocentric prospective study. CCA was carried out by software-based automated subtraction of imaging features in late versus early T1-weighted sequences after contrast agent application. Two experienced neuroradiologists evaluated CCA with respect to PsP/RN and PD being blinded for histological findings. The radiological assessment was compared with the histopathological results, and its accuracy was calculated statistically. Results A total of 33 patients were included; 16 (48.5%) were treated because of a primary brain tumor (BT), and 17 (51.1%) because of a secondary BT. In one patient, CCA was technically infeasible. The accuracy of CCA in predicting the histological result was 0.84 [95% confidence interval (CI) 0.67-0.95; one-sided P = 0.051; n = 32]. Sensitivity and specificity of CCA were 0.93 (95% CI 0.66-1.00) and 0.78 (95% CI 0.52-0.94), respectively. The accuracy in patients with secondary BTs was 0.94 (95% CI 0.71-1.00) and nonsignificantly higher compared with patients with primary BT with an accuracy of 0.73 (95% CI 0.45-0.92), P = 0.16. Conclusions In this study, CCA was a highly accurate, easy, and helpful method for distinguishing PsP or RN from PD after cranial radiotherapy, especially in patients with secondary tumors after radiosurgical treatment. CCA is accurate in distinguishing treatment reactions from true PD. CCA was more accurate for irradiated metastases than primary BTs. CCA is not feasible for lesions with no contrast media uptake.
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P05.01 Prospective validation trial of magnetic resonance imaging based Contrast Clearance Analysis (CCA) to differentiate between pseudoprogression/radiation necrosis and progressive disease following cranial radiotherapy. Neuro Oncol 2021. [DOI: 10.1093/neuonc/noab180.077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Pseudoprogression (PsP) or radiation necrosis (RN) may frequently occur after cranial radiotherapy and show a similar imaging pattern compared to progressive disease (PD). Even for experienced neuroradiologists, it remains challenging to distinguish between these clinically relevant disease states. We aimed to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) based Contrast Clearance Analysis (CCA) in this clinical setting.
MATERIAL AND METHODS
Patients with equivocal imaging findings after cranial radiotherapy were consecutively included into this monocentric prospective study. Assuming a true accuracy of 90% and setting the significance level to 0.05, N=33 patients are required to show that accuracy is larger than 70% with a power of 80% using a one-sided binomial test. CCA was performed by subtraction of imaging features in late vs early T1-weighted sequences after contrast-agent application. Two experienced neuroradiologists evaluated CCA with respect to PsP/RN and PD being blinded for FET PET and histological findings; histopathological diagnosis was based on stereotactic biopsy or resection for space-occupying processes. The radiological assessment was compared with the histopathological results, and its accuracy was calculated statistically.
RESULTS
Thirty-three patients were included; sixteen (48.5%) were treated because of a primary brain tumors, and 17 (51.1%) with brain metastases. In one patient, CCA was technically infeasible. The accuracy of CCA in predicting the histological result was 0.84 (95% CI 0.67–0.95; one-sided p=0.05; N=32). An accuracy of 0.85 (95% CI 0.68–0.95; one-sided p=0.04) would have been obtained in case of a correct classification in the non-analyzable case. Sensitivity and specificity of CCA were 0.93 (95%-CI 0.66–1.00) and 0.78 (95% CI 0.52–0.94), respectively. The accuracy in metastases patients was 0.94 (95% CI 0.71 - 1.00) and non-significantly higher compared to primary brain tumor patients with accuracy of 0.73 (95% CI 0.45 - 0.92), p=0.16.
CONCLUSION
In this study, CCA was a highly accurate, easy and helpful method for distinguishing PsP or RN from PD after cranial radiotherapy, especially in brain metastases patients after radiosurgical treatment.
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PH-0359: Blood plasma based risk stratification of glioblastoma patients. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00383-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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360O Telomerase reverse transcriptase (TERT) promoter mutation and O6-methylguanine DNA methyltransferase (MGMT) promoter methylation-mediated sensitivity to temozolomide in IDH-wildtype glioblastoma: Is there a link? Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.08.469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Bevacizumab as a treatment option for radiation necrosis after cranial radiation therapy: a retrospective monocentric analysis. Strahlenther Onkol 2019; 196:70-76. [PMID: 31586230 DOI: 10.1007/s00066-019-01521-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/11/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE Radiation necrosis is a possible adverse event after cranial radiation therapy and can cause severe symptoms, such as an increased intracranial pressure or neurological deterioration. The vascular endothelial growth factor (VEGF) inhibitor bevacizumab (BEV) has been shown to be a feasible therapeutic option for symptomatic radiation necrosis, either when traditional antiedematous steroid treatment fails, or as an alternative to steroid treatment. However, to the best of our knowledge, only one randomized study with a rather small cohort exists to prove a beneficial effect in this setting. Therefore, further real-life data are needed. This retrospective monocentric case study evaluates patients who received BEV due to radiation necrosis, with a specific focus on the respective clinical course. METHODS Using the internal database for pharmaceutical products, all patients who received BEV in our department were identified. Only patients who received BEV as symptomatic treatment for radiation necrosis were included. Patient characteristics, symptoms before, during, and after treatment, and the use of dexamethasone were evaluated using medical reports and systematic internal documentation. The symptoms were graded using CTCAE version 5.0 for general neurological symptoms. Symptoms were graded directly before each cycle and after the treatment (approximately 6 weeks). Additionally, the daily steroid dose was collected at these timepoints. Patients who either improved in symptoms, received less dexamethasone after treatment, or both were considered to have a benefit from the treatment. RESULTS Twenty-one patients who received BEV due to radiation necrosis were identified. For 10 patients (47.6%) symptoms improved and 11 patients (52.4%) remained clinically stable during the treatment. In 14 patients (66.7%) the dexamethasone dose could be reduced during therapy, 5 patients (23.8%) received the same dose of dexamethasone before and after the treatment, and 2 patients (9.5%) received a higher dose at the end of the treatment. According to this analysis, overall, 19 patients (90.5%) benefited from the treatment with BEV. No severe adverse effects were reported. CONCLUSION BEV might be an effective and safe therapeutic option for patients with radiation necrosis as a complication after cranial radiation therapy. Patients seem to benefit from this treatment by improving symptomatically or through reduction of dexamethasone.
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P14.108 Bevacizumab versus alkylating chemotherapy in recurrent glioblastoma. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
The use of alkylating chemotherapy versus bevacizumab for recurrent glioblastoma remains controversial. Here we tested the hypothesis that the activity of alkylators, but not that of bevacizumab, would be associated with the O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status
PATIENTS AND METHODS
We analyzed a cohort of patients treated at centers of the German Glioma Network or the University Hospital Zurich with alkylating agent-based chemotherapy (n=260) or bevacizumab without or with irinotecan (n=84) for first recurrence of glioblastoma. Outcome was stratified for MGMT status and cross-over to bevacizumab or alkylators at further tumor progression.
RESULTS
Median post-recurrence survival-1 (PRS-1) for patients receiving alkylating agent chemotherapy at first recurrence was longer than for patients receiving bevacizumab (11.1 versus 7.4 months, p<0.001). The use of alkylating agents was associated with longer PRS-1 for patients with a methylated versus an unmethylated MGMT promoter (p=0.017). For patients receiving bevacizumab, PRS-1 was not different with or without MGMT promoter methylation. PRS-1 was longer in the group receiving alkylating chemotherapy compared to bevacizumab for patients with a methylated (p<0.001) or unmethylated MGMT promoter (p=0.034). For patients with alkylators at first recurrence receiving bevacizumab at any further recurrence, PRS-1 was longer than in patients receiving bevacizumab first and alkylators thereafter (p=0.002).
CONCLUSION
This study confirms limited value of bevacizumab in recurrent glioblastoma independent of MGMT status. Alkylating agents have activity in recurrent glioblastoma, especially in the context of a methylated MGMT promoter.
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P14.02 Influence of individual CpG methylation status on outcome in adult patients with glioblastoma multiforme receiving alkylating agent treatment. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background: Methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) promotor causes gene silencing and has been associated with a favourable prognosis in patients with glioblastoma multiforme (GBM) receiving alkylating chemotherapy. However, analysis of MGMT promotor methylation is usually reported as a cut-off depending on the results of the correspondent CpG site testing. This approach disregards a possible heterogeneity concerning the methylation status within the individual CpG sites and its possible association with prognosis in GBM patients. The current study aimed at elucidating the association between methylation of CpG sites 74–98 within the MGMT promotor region and outcome in GBM patients receiving alkylating agents.
Material and Methods: Individual methylation status of 230 patients with histologically proven GBM following concomitant radio-chemotherapy with TMZ after stereotactic biopsy or open tumor resection (OTR) was assessed by the Sanger sequencing (Sseq) approach. Methylation of CpG sites 74–98 within the MGMT promotor region was defined according to a ratio of cytosine /thymine peak >50%. The total number of methylated CpG sites as well as clinical factors such as age, Karnofsky Performance Score (KPS) and mode of surgical procedure were correlated with outcome using proportional hazards models. In a subset of 34 patients, a correlation between individual CpG methylation and MGMT mRNA expression was performed.
Results: Median progression-free (PFS) and overall survival (OS) were 7.8 and 14.6 months, respectively. Alongside younger age, KPS> 80 and OTR, the cumulative total number of methylated loci within the CpG sites 74–98 was strongly associated with both PFS and OS and retained its prognostic influence on outcome in multivariate models (p <0.001). Furthermore, a linear coherence between the total number of methylated CpG sites 74–98 and survival parameters could be observed. Moreover, low number of methylated CpG sites was observed in tumor specimen with a high mRNA expression and vice versa (Spearman correlation coefficient: -0.62).
Conclusion: In contrast to the concept of dichotomizing the MGMT promotor status into ‘methylated’ and ‘non-methylated’, our approach shows a clear heterogeneity within the methylation status of the CpG sites 74–98 within the GBM tumor specimens. Our data suggest a strong correlation between outcome and the total number of methylated CpG sites, thus an up-front analysis of the individual GpC site methylation status prior to initiation of alkylating chemotherapy might help to improve treatment response in GBM patients.
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State of Practice: Endovascular Treatment of Acute Aneurysmal SAH in Germany. AJNR Am J Neuroradiol 2017; 38:1574-1579. [PMID: 28619838 DOI: 10.3174/ajnr.a5260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/06/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Acute aneurysmal SAH is a severe disease that requires prompt treatment. Endovascular coiling and neurosurgical clipping are established treatment options. Our intention was to determine the state of current practice in acute aneurysmal SAH treatment in Germany, with emphasis on logistic and temporal aspects. MATERIALS AND METHODS We interviewed 74 German university and nonuniversity hospitals with an anonymous questionnaire comprising 15 questions concerning the practice of treatment and diagnostics of acute aneurysmal SAH at their respective institutions. The response rate was 74% among all institutions (55/74); among university hospitals, 77%; and among nonuniversity hospitals, 72%. RESULTS The majority of all aneurysms were treated endovascularly (66% of acute aneurysmal SAH, 66% of unruptured aneurysms). Treatment on weekends was provided by 100% of endovascular and 96% of neurosurgical facilities. Average patients with acute aneurysmal SAH were not treated during the night (98%). Seventy percent of endovascular and 78% of neurosurgical treatments were not started later than 8:00 pm. Fifty-three percent of hospitals would not start a same-day diagnostic angiography in acute aneurysmal SAH if treatment was scheduled for the following day. Eighty-two percent of all centers performed DSA after clipping to evaluate the treatment results. CONCLUSIONS Our survey gives a detailed summary of the current practice of endovascular treatment and related topics in acute aneurysmal SAH in Germany and also reveals considerable changes in practice in comparison with older data.
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Suizidalität bei Pathologischen Glücksspielern: Ergebnisse der PAGE-Studie. SUCHTTHERAPIE 2015. [DOI: 10.1055/s-0035-1557673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Assessing and treating alcohol relapse risk in liver transplantation candidates. Alcohol Alcohol 2015; 50:164-72. [PMID: 25557607 DOI: 10.1093/alcalc/agu096] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In Europe between 30 and 50% of all liver transplantations (LTX) are done within the context of chronic end-stage alcoholic liver disease (ALD). However, post-operatively 20-25% of these patients lapse or relapse into heavy alcohol use. Thus, assessment of alcohol relapse risk before enlisting and therapeutic follow-up during and after LTX is of utmost importance. However, as yet there are enormous differences between European countries and between transplant centers, with regard to the assessment methods and criteria and the implementation of therapeutic follow-up. Only the so-called '6-month abstinence' rule is widely used. However, there are not much scientific data validating its use in predicting relapse. Thus, there is a clear need of a more homogeneous approach, which was the focus of a symposium of the European Federation of Addiction Societies during the 14th conference of the European Society for Biomedical Research on Alcoholism, 2013 (ESBRA), entitled 'Liver transplantation: A European perspective'. In a follow-up on this symposium, the authors aim to sum up the evidence of psychiatric assessment criteria and psychiatric treatment interventions relevant in the context of patient selection and patient follow-up within ALD transplantation procedures. Based upon these findings, we propose elements of a procedure that can serve as a first step toward a model of good practice regarding addiction-specialist input within the pre- and post-transplantation period.
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O7.09 * [68GA]-DOTATATE-PET IMAGING PREDICTS SOMATOSTATIN RECEPTOR II EXPRESSION IN MENINGIOMAS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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O5.06 * CYSTIC CRANIOPHARYNGIOMAS: MICROSURGICAL OR STEREOTACTIC TREATMENT? Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Alkohol- und Benzodiazepinkonsum bei älteren und hochbetagten Menschen – Ergebnisse aus dem INTERREG-Projekt Alter und Sucht. SUCHTTHERAPIE 2014. [DOI: 10.1055/s-0034-1382045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Prevalence of suicide attempts in pathological gamblers in a nationwide Austrian treatment sample. Gen Hosp Psychiatry 2014; 36:342-6. [PMID: 24630895 DOI: 10.1016/j.genhosppsych.2014.01.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND For pathological gambling (PG), a 12-month prevalence rate of up to 0.66% has been reported. Multiple financial, occupational and relationship problems and losses, humiliation of the person and the environment are possible side effects and may lead to hopelessness, suicidal ideation and suicidal behavior. Suicide attempt rates among pathological gamblers of between 4% and 40% and suicidal ideation of between 12% and 92% have been reported. AIM This study aims at assessing the prevalence of suicide attempts in PG and at elucidating differences between the patients with and without suicide attempt history (SAH) in a large nationwide Austrian sample. METHODS Between 2002 and 2011, the Austrian Society for the Research of Non-Substance Related Addiction collected 862 questionnaires of pathological gamblers undergoing outpatient and inpatient treatment for PG in Austria. RESULTS (a) Of all pathological gamblers, 9.7% had an SAH. (b) The SAH group suffered significantly more from a comorbid disorder and was more often in previous inpatient treatments. (c) The SAH patients had a longer time of an abstinence period in their PG career. DISCUSSION One in 10 pathological gamblers has an SAH, demonstrating the relevance of suicidality in this population. Significant differences for several parameters were found for PG with and without SAH. However, a regression analysis only explained 15% of the variance. This suggests that suicidality must be considered in pathological gamblers in general.
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Gross total but not incomplete resection of glioblastoma prolongs survival in the era of radiochemotherapy. Ann Oncol 2013; 24:3117-23. [DOI: 10.1093/annonc/mdt388] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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22
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23
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S22 * LIVER TRANSPLANTATION: A EUROPEAN PERSPECTIVE SYMPOSIUM OF THE EUROPEAN FEDERATION OF ADDICTION SOCIETES (EUFAS) II. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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25
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[Direct metabolites of ethanol as biological markers of alcohol use: basic aspects and applications]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2013; 81:493-502. [PMID: 23856980 DOI: 10.1055/s-0033-1335586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In addition to self reports and questionnaires, biomarkers are of relevance in the diagnosis of and therapy for alcohol use disorders. Traditional biomarkers such as gamma-glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to the influence of age, gender and non-alcohol related diseases, among others. Direct metabolites of ethanol such as ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake - EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programmes, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and foetal alcohol syndrome. Due to their properties, they open up new perspectives for prevention, interdisciplinary cooperation, diagnosis of and therapy for alcohol-related problems.
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Abstract
Gliomas are more or less diffuse tumours with the ability to infiltrate surrounding functional brain tissue. Thus, curative surgical treatment generally cannot be achieved. Despite these limitations, open tumour resection represents one of the mainstays in glioma treatment settings. Beyond tissue sampling for accurate histological and molecular genetic evaluation, decompressive effects in the case of space occupying tumours and oncologically relevant cytoreductive effects of microsurgery have been reported in selected patients with glioma of different grades. This paper provides practical considerations in order to integrate the concept of a personalized surgical therapy into the prognostic network of low- and high-grade gliomas, covering both microsurgery and stereotactic biopsy techniques.
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NEUROSURGICAL TREATMENTS. Neuro Oncol 2012. [DOI: 10.1093/neuonc/nos230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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CLIN-NEURO/MEDICAL ONCOLOGY. Neuro Oncol 2012. [DOI: 10.1093/neuonc/nos229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstracts of the 10th Congress of the European Association of NeuroOncology. Marseille, France. September 6-9, 2012. Neuro Oncol 2012; 14 Suppl 3:iii1-109. [PMID: 22977921 DOI: 10.1093/neuonc/nos183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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MEDICAL AND NEURO-ONCOLOGY. Neuro Oncol 2011. [DOI: 10.1093/neuonc/nor152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Hot spots in dynamic (18)FET-PET delineate malignant tumor parts within suspected WHO grade II gliomas. Neuro Oncol 2011; 13:307-16. [PMID: 21292686 DOI: 10.1093/neuonc/noq196] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Molecular imaging studies have recently found inter- and intratumoral heterogeneity in World Health Organization (WHO) grade II gliomas. A correlative analysis with tumor histology, however, is still lacking. For elucidation we conducted the current prospective study. Fifty-five adult patients with an MRI-based suspicion of a WHO grade II glioma were included. [F-18]Fluoroethyltyrosine ((18)FET) uptake kinetic studies were combined with frame-based stereotactic localization techniques and used as a guide for stepwise (1-mm steps) histopathological evaluation throughout the tumor space. In tumors with heterogeneous PET findings, the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and expression of mutated protein isocitrate dehydrogenase variant R132H (IDH1) were determined inside and outside of hot spot volumes. Metabolic imaging revealed 3 subgroups: the homogeneous WHO grade II glioma group (30 patients), the homogeneous malignant glioma group (10 patients), and the heterogeneous group exhibiting both low- and high-grade characteristics at different sites (15 patients). Stepwise evaluation of 373 biopsy samples indicated a strong correlation with analyses of uptake kinetics (p < 0.0001). A homogeneous pattern of uptake kinetics was linked to homogeneous histopathological findings, whereas a heterogeneous pattern was associated with histopathological heterogeneity; hot spots exhibiting malignant glioma characteristics covered 4-44% of the entire tumor volumes. Both MGMT and IDH1 status were identical at different tumor sites and not influenced by heterogeneity. Maps of (18)FET uptake kinetics strongly correlated with histopathology in suspected grade II gliomas. Anaplastic foci can be accurately identified, and this finding has implications for prognostic evaluation and treatment planning.
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-Omics and Prognostic Markers. Neuro Oncol 2010. [DOI: 10.1093/neuonc/noq116.s8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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MGMT promoter methylation status and DNA mismatch repair genes in paired primary and recurrent glioblastoma: A translational study of the German Glioma Network. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.2076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Integration of metabolic imaging and molecular genetic profiling of serial stereotactic biopsies are valuable for histological discrimination of oligodendrogliomas, mixed oligoastrocytomas and astrocytomas WHO° II/III. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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35
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In vitro investigation of Varizella zoster virus as an oncolytic virus in glioblastoma therapy. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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KLF-8: A novel integrin signalling molecule, which enhances malignant proliferation in gliomas and is expressed grade dependent. AKTUELLE NEUROLOGIE 2007. [DOI: 10.1055/s-2007-988039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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[P78]: CD133
+
/Musashi‐I
+
/CD34
−
neural stem cells in gliomas of different grades. Int J Dev Neurosci 2006. [DOI: 10.1016/j.ijdevneu.2006.09.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Expression of VEGFR3 in glioma endothelium correlates with tumor grade. J Neurooncol 2006; 82:141-50. [PMID: 17115285 DOI: 10.1007/s11060-006-9272-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Accepted: 09/13/2006] [Indexed: 11/27/2022]
Abstract
Angiogenic processes are regulated by vascular endothelial growth factors (VEGFs) and their receptors VEGFR1 (Flt-1), 2 (Flk-1) and 3 (Flt-4). While VEGFR2 is thought to play a central role in tumor angiogenesis, anti-angiogenic therapies targeting VEGFR2 in glioma models can show escape phenomena with secondary onset of angiogenesis. The purpose of this study was to find explanations for these processes by searching for alternative pathways regulating glioma angiogenesis and reveal a correlation with tumor grade. Thus, VEGFR3, which is not expressed in normal brain, and its ligands VEGF-C and -D, were assessed in high grade (WHO degrees IV, glioblastomas, GBM) and low grade gliomas [WHO degrees II astrocytomas (AII)]. In all GBM, a strong protein expression of VEGFR3 was found on tumor endothelium, VEGF-C and -D expression was found on numerous cells in areas of high vascularization. On RNA level, a significant up-regulation of VEGFR3 was detected in GBM compared to AII and non-neoplastic brain. In AII, only very moderate VEGFR3, VEGF-C and -D expression was found on protein and RNA level indicating a correlation of VEGFR3 expression with tumor grade. VEGFR3 signal in both grades was found predominantly on endothelial cells, confirmed by VEGFR3 expression on isolated CD31 positive cells and the expression of various endothelial markers on VEGFR3-positive cells isolated from GBM. The demonstration of a complete angiogenic signaling system that is dependent on tumor grade may influence the traditional paradigm of glioma angiogenesis and may provide a basis for more effective anti-angiogenic treatment strategies.
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P34. Expression of lymphangiogensis related VEGFR3 in malignant gliomas. EJC Suppl 2006. [DOI: 10.1016/j.ejcsup.2006.04.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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P32. CD133 positive “Cancer stem cells” in gliomas of different grades. EJC Suppl 2006. [DOI: 10.1016/j.ejcsup.2006.04.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Persistently modified h-channels after complex febrile seizures convert the seizure-induced enhancement of inhibition to hyperexcitability. Nat Med 2001; 7:331-7. [PMID: 11231632 PMCID: PMC3382967 DOI: 10.1038/85480] [Citation(s) in RCA: 333] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Febrile seizures are the most common type of developmental seizures, affecting up to 5% of children. Experimental complex febrile seizures involving the immature rat hippocampus led to a persistent lowering of seizure threshold despite an upregulation of inhibition. Here we provide a mechanistic resolution to this paradox by showing that, in the hippocampus of rats that had febrile seizures, the long-lasting enhancement of the widely expressed intrinsic membrane conductance Ih converts the potentiated synaptic inhibition to hyperexcitability in a frequency-dependent manner. The altered gain of this molecular inhibition-excitation converter reveals a new mechanism for controlling the balance of excitation-inhibition in the limbic system. In addition, here we show for the first time that h-channels are modified in a human neurological disease paradigm.
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The chondroitin sulphate proteoglycan brevican is upregulated by astrocytes after entorhinal cortex lesions in adult rats. Eur J Neurosci 2000; 12:2547-58. [PMID: 10947829 DOI: 10.1046/j.1460-9568.2000.00109.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The chondroitin sulphate proteoglycan brevican is one of the most abundant extracellular matrix molecules in the adult rat brain. It is primarily synthesized by astrocytes and is believed to influence astroglial motility during development and under certain pathological conditions. In order to study a potential role of brevican in the glial reaction after brain injury, its expression was analysed following entorhinal cortex lesion in rats (12 h, 1, 2, 4, 10, 14 and 28 days and 6 months post lesion). In situ hybridization and immunohistochemistry were employed to study brevican mRNA and protein, respectively, in the denervated outer molecular layer of the fascia dentata and at the lesion site. In both regions brevican mRNA was upregulated between 1 and 4 days post lesion. The combination of in situ hybridization with immunohistochemistry for glial fibrillary acidic protein demonstrated that many brevican mRNA-expressing cells are astrocytes. In the denervated zone of the fascia dentata, immunostaining for brevican was increased by 4 days, reached a maximum by 4 weeks and remained detectable up to 6 months post lesion. Electron microscopic immunocytochemistry showed that brevican is a component of the extracellular matrix compartment. At the lesion site a similar time course of brevican upregulation was observed. These data demonstrate that brevican is upregulated in areas of brain damage as well as in areas denervated by a lesion. They suggest a role of brevican in reactive gliosis and are compatible with the hypothesis that brevican is involved in the synaptic reorganization of denervated brain areas.
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Entorhinal cortex lesion in adult rats induces the expression of the neuronal chondroitin sulfate proteoglycan neurocan in reactive astrocytes. J Neurosci 1999; 19:9953-63. [PMID: 10559403 PMCID: PMC6782976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The chondroitin sulfate proteoglycan neurocan is a major component of brain extracellular matrix during development. Neurocan is primarily synthesized by neurons and has the ability to interact with cell adhesion molecules involved in the regulation of cell migration and axonal growth. Within the first weeks postnatally, neurocan expression is strongly downregulated. To test whether neurocan is reexpressed in areas of axonal growth (sprouting) after brain injury, the time course of neurocan expression was analyzed in the denervated fascia dentata of the rat after entorhinal cortex lesion (12 hr; 1, 2, 4, and 10 d; 2 and 4 weeks; and 6 months after lesion). In the denervated zone, immunohistochemistry revealed neurocan-positive astrocytes by 2 d after lesion and a diffuse labeling of the extracellular matrix at all later time points. Electron microscopy confirmed the deposition of neurocan in the extracellular matrix compartment. In situ hybridization demonstrated a strong upregulation of neurocan mRNA within the denervated outer molecular layer 1 and 4 d after lesion. The combination of in situ hybridization with immunohistochemistry for glial fibrillary acidic protein demonstrated that the neurocan mRNA-expressing cells are astrocytes. These data demonstrate that neurocan is reexpressed in the injured brain. In contrast to the situation during development, astrocytes, but not neurons, express neurocan and enrich the extracellular matrix with this molecule. Similar to the situation during development, neurocan is expressed in an area of active axon growth, and it is suggested that neurocan acts to maintain the boundaries of the denervated fascia dentata after entorhinal cortex lesion.
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